A16 soybeans having low linolenic acid content and descendents

ABSTRACT

A novel soybean seed and plant designated A16 having ATCC Accession No. and its descendents are provided. Such soybean exhibits an unusually low linolenic acid (C18:3) content of less than 2.5% by weight based upon the total fatty acid content in the endogenously formed vegetable oil.

This Application is a division of Ser. No. 08/376,535, filed Jan. 20,1995, (now U.S. Pat. No. 5,534,425) which is a continuation of Ser. No.08/180,115, filed Jan. 12, 1994 (now abandoned), which is a continuationof Ser. No. 07/839,242, filed Feb. 20, 1992 (now abandoned), which is acontinuation-in-part of Ser. No. 07/645,244, filed Jan. 24, 1991 (nowabandoned), which is a continuation-in-part of Ser. No. 07/445,393,filed Dec. 5, 1989 (now abandoned), which is a continuation of Ser. No.07/151,705, filed Feb. 3, 1988 (now abandoned).

FIELD OF THE INVENTION

This invention relates to soybean seeds and to oils and other productsmade therefrom and, more particularly, to soybean seeds and oils, andmethods for producing such seeds and oils, characterized by extremelylow levels of linolenic acid.

BACKGROUND OF THE INVENTION

Soybean seeds represent perhaps the most significant oilseed in theworld. Soybean oil makes up approximately 28% of the world supply offats and oils, has been considered to be the major vegetable oilproduced and consumed in the United States, and more than 90% of thesoybean oil is used in food products (World Soybean Research ConferenceIII Proceeding, Shibles, R. (Ed.) 1985).

Although soybean oil represents an important worldwide food source,flavor and stability problems reduce its utility in many applications.Soybean oil contains five different types of fatty acids. These fivetypes of fatty acids are: palmitic acid (16:0), which averages about 11%of the total fatty acids; stearic acid (18:0), which averages about 4%of the total fatty acids; oleic acid (18:1), which averages about 20% ofthe total fatty acids; linoleic acid (18:2), which averages about 57% ofthe total fatty acids; and linolenic acid (18:3), which averages about8% of the total fatty acids. The flavor stability problem of soybean oilhas been attributed to the oxidation of its fatty acids, particularly tothe oxidation of linolenic acid.

The unsaturated fatty acids in soybean oil are susceptible to oxidation;and the polyunsaturated fatty acids, linoleic and linolenic, oxidizemore rapidly than oleic acid. The oxidized fatty acids apparentlydecompose to form volatile flavor compounds. It is not clear whylinolenic acid contributes so significantly to the flavor and stabilityof oils; but, based upon experiments using blends of oils with differentpercentages of linolenic acid, all oils containing more than about 1%linolenic acid or so appear to share this property to some extent. Formore than 35 years, the flavor and stability problems of soybean oilhave been attributed to the high linolenic acid level of the soybean oil(Dutton et al., J. Am. Oil Chem. Soc., 28:115, 1951).

To attempt to obviate the flavor and stability problems of soybean oildue to the linolenic acid content, various processes have been tried.Such processing includes (1) minimizing the ability of the fatty acidsto undergo oxidation by adding metal chelating agents or packaging inthe absence of oxygen, or (2) removal of the endogenous linolenic acidby selective hydrogenation. These approaches have not been entirelysatisfactory. Such additional processing is expensive, time consuming,not completely effective and often generates undesirable by-products.Thus, while selective hydrogenation to reduce the linolenic acid contentmay improve oil stability, this also generates positional and geometricisomers of the unsaturated fatty acids that are not present in naturalsoybean oil.

The inability to solve the problem adequately, together with theundesirable aspects of the processing technology described herein,reduces the utility of soybeans, especially where such processingtechnology is either unavailable or is economically inappropriate orwhere consumer attitudes discourage the use of selective hydrogenation.

Perhaps because of the limitations of such processing technology andbecause of the worldwide significance of soybean oil as a food source,considerable effort has been expended over many years to attempt tounderstand the genetic mechanism which controls the linolenic acid levelin soybeans. Indeed, studies on this subject date back to at least 1949.According to Howell et al., as many as five different genes may controlthe linolenic acid level in soybeans (J. Am. Oil Chem. Soc., 26:126,1949). Investigations into the biochemical mechanism suggest thatlinolenic acid results from successive desaturations of first oleic acidand second linoleic acid. Thus, genes controlling at least two differentdesaturase systems may be involved. So far, the genes which control thelinolenic acid level of soybeans have not been fully identified; and thebiochemical pathway has not been fully elucidated.

Even the mode of inheritance of linolenic acid in soybeans is unclearbecause various studies over the years have presented conflictingresults. For example, early investigation suggested that the linolenicacid content in soybeans was maternally controlled. A later studysuggested the mechanism of inheritance was even more complicated, beingpartially maternally and partially embryonically controlled (Wilson etal., Regulation of Linolenic Acid in Soybeans and Gene Transfer of HighYielding, High Protein Germplasm, R. A. Baldwin (Ed.), Proceedings ofthe World Conference on Emerging Technologies in the Fats and OilsIndustry, Am. Oil Chem. Soc., Champaign, Ill., 1986). The Wilson et al.study thus reports that the genes which regulate oleic acid desaturationare controlled by the maternal parent, while the genes which controllinoleic desaturation are governed by the embryonic genotype.

Complications also arise because it has been long recognized that thelinolenic acid content of soybeans is highly dependent upon theenvironment in which the seeds are grown (Howell et al., Agron. J.45:526, 1953). Such environmental factors are said to includetemperature, photoperiod (viz.--day length), the geographical locationand planting date.

In summary, despite the substantial effort over the years, the geneticmechanism controlling the linolenic acid content in soybeans is not allthat well understood. Genetic research to provide soybeans characterizedby reduced levels of linolenic acid is thus quite complex. There islittle to guide efforts of this sort. Research is accordingly largelyempirical.

Yet, despite the relative lack of understanding of the genetic mechanismwhich controls the level of linolenic acid content in soybeans,substantial work over the years has been carried out to attempt toisolate soybean lines having low levels of linolenic acid, as well asattempts to use genetic manipulation to develop a soybean linecharacterized by low levels of linolenic acid. The lowest level oflinolenic acid in the oil of natural soybean germplasm accessions wasfound to be 4.2% (Kleinman and Cavins, J. Am. Oil Chem. Soc., 59:305A,1982).

Tripathi et al., Indian J. Agric. Res., 1975, 9(4):220-222, Note On TheQuality Constituents Of Soybean (Glycine Max (L) Merrill) Varieties, didreport, among other things, the fatty acid contents of what were statedto be 12 soybean varieties grown at the Oilseed Research Farm,Kalianpur, Kanpur, during kharif, 1970. While the linolenic acidcontents reported vary from 0.0 to 5.3, such contents were calculated bythe Scholfield and Bull formulae (Tripathi et al., referencing Bailey,1945, Industrial Oil and Fat Products, Interscience Publishers, Inc.,New York). In general, Scholfield and Bull's methodology predicted fattyacid composition from the iodine value. Their data were scattered aboutthese linear predictions; and, for linolenic acid, a standard error of1.5% was reported.

In the first place, the availability of the 12 soybean varietiesreferenced by Tripathi et al. is uncertain. Applicants have maderepeated attempts to obtain samples of such varieties and have not beensuccessful in securing all of them.

Secondly, and importantly, what has been determined on the basis ofsamples provided is that there is no correlation between the linolenicacid values reported by Tripathi et al. and those determined by gaschromatography. Gas chromatography is the current analytical standardused for fatty acid analysis. Set forth below, for all samples obtained,is a comparison of the linolenic acid values reported in Tripathi et al.with those obtained by gas-liquid chromatography (GLC):

    ______________________________________                                                Tripathi et al.                                                                        GLC Values, %                                                Variety   Values, %  Seed From U.S..sup.1                                                                      Seed from India.sup.2                        ______________________________________                                        Bragg     4.5        7.6         5.8                                          Type 49   4.9        --          5.9                                          Lee       3.7        6.7         4.0                                          Improved Pelican                                                                        2.4        7.2         7.0                                          Punjab-1  0.4        6.1         5.6                                          IC2716    1.0        --          4.4                                          Type 33   5.3        --          --                                           Type 64   0.0        --          --                                           Type 1    1.4        --          --                                           IC217     2.8        --          5.9                                          IC222     4.1        --          --                                           IC213     4.2        --          --                                           ______________________________________                                         .sup.1 Seed produced in United States and obtained from USDA, Soybean         Production Research, Stoneville, Mississippi.                                 .sup.2 Seed obtained from the National Bureau of Plant Genetic Resources,     New Delhi, India.                                                        

In summary, based upon what applicants have found, there would be nobasis for asserting that any of the varieties referenced by Tripathi etal. were varieties having low linolenic acid contents when such contentsare determined by gas chromatography. Rather, these varieties appear tohave rather typical linolenic acid contents, contents certainly abovethe minimum reported by Kleinman et al. for natural soybean germplasmaccessions.

Hybridization work to reduce the linolenic acid of soybeans goes back asfar as 1961. White et al. identified an F₂ plant obtained byhybridization with only 3.35% linolenic acid (White, Quackenbush andProbst, Occurrence and Inheritance of Linolenic and Linoleic Acid inSoybean Seeds, J. Am. Chem. Soc., vol. 38, pp. 113-117, 1961). However,this level was not maintained in succeeding generations.

Reported in 1975, the present applicants utilized recurrent selection toproduce soybean strains having levels of linolenic acid of about 5.5%(Fette Seifen Anstrichm., 77:97-101, 1975). Wilson and Burton isolatedtwo different lines, designated N78-2245 and PI123440. These lines wereselected for their significant levels of oleic acid, linoleic acid andlinolenic acid contents. From this experimentation, two genetic systemswere discovered, one that primarily governs oleic acid desaturation anda second that acts genotypically upon linoleic desaturation. These twogene loci determine the low linolenic acid content (Crop Science,21:788, 1981).

Wilcox et al. treated soybeans with ethyl methane sulfonate (EMS) toproduce a mutant designated C1640 (J. Am. Oil Chem. Soc., 61:97, 1984).The level of linolenic acid averaged 3.4%. It was stated that thelinolenic acid trait could be transferred to other lines bybackcrossing.

The present applicants were able to produce a mutant line A5 in 1983which had an average of from about 2.9 to 4.1 percent linolenic aciddepending upon the growth environment. This line was selected from theprogeny of soybeans mutagenized with EMS (Crop Science, 23:192, 1983).More particularly, the mutant line A5 had an average linolenic acidpercentage of 4.1% in one planting in Iowa and an average of 2.9% in twoplantings in Puerto Rico. In a series of plantings involving fivestates, the average linolenic acid concentration for the A5 mutant was3.8%. As will be discussed hereinafter, data generated in conjunctionwith the present invention revealed some A5 seeds having lower linolenicacid contents than the 2.9% previously noted. The seed of A5 (Reg. No.GP44) is publicly available and has been distributed by the Committeefor Agricultural Development, Iowa State University, Ames, Iowa 50011,since 1983. A5 seed also is maintained by the Iowa Agriculture and HomeEconomics Experiment Station. Additionally, 2,500 seeds of A5 weredeposited on Dec. 5, 1995 under the Budapest Treaty in the American TypeCulture Collection (ATCC) at 12301 Parklawn Drive, Rockville, Md. 20852,U.S.A., and have been assigned ATCC Accession No. 97371.

The production of fatty acids in other plant systems, such as thesunflower, have been described, for example, in U.S. Pat. 4,627,192. Inthis case, a sunflower was disclosed which had a high oleic acid contentand a low linoleic acid content.

A further interest for some applications would be the development of asoybean line characterized by not only low linolenic acid content, butalso by a relatively high stearic acid content. More particularly, theproduction of plastic fats (e.g.--shortenings and margarines) withdesirable physical properties can benefit from a soybean line having arelatively high stearic acid content. The A6 line (Reg. No. GP45)developed by applicants provides a soybean line having relatively highstearic acid contents (i.e. --28 to 30% or so), but such line has arelatively high linolenic acid content. A6 seed has been distributed bythe Committee for Agricultural Development, Iowa State University, Ames,Iowa 50011, since 1983. A6 seed is maintained by the Iowa Agricultureand Home Economics Experiment Station.

Yet a further interest would be the development of a soybean linecharacterized by not only low linolenic acid content, but also by amoderately high palmitic acid content, i.e.--above 11%, more desirablyin the range of 13 or 14 to 16% or so. Soybean lines having suchmoderately high palmitic acid contents may be desired for specificplastic fats; and, while current soybean lines can provide the desiredpalmitic acid contents, no existing soybean line or variety combines thedesired palmitic acid content with a low linolenic acid content.

A still further interest would be the development of soybean linescharacterized by not only low linolenic acid content, but also by arelatively high oleic acid content. Thus, for product applications whereenhanced shelf-life or storage stability is required, it would bedesirable to provide soybean lines characterized by a relatively higholeic acid and a relatively low linolenic acid content. Soybean lineshaving such characteristics would be highly desirable for commercialfrying applications such as, for example, making potato chips or thelike. It would even be more desirable for some applications to providesoybean lines having such characteristics that also have relatively lowlevels of saturated fatty acids.

An additional and related interest would be the development of soybeanlines characterized by not only low linolenic acid content, but also bya relatively low palmitic acid content. More specifically, a majorcompetitor of soybeans for the vegetable oil market is canola. Canolahas been promoted as a healthier oil than soybean oil because of itsrelatively lower saturated fatty acid content. It would be a significantadvance to be able to provide soybean oil that not only has the benefitsassociated with a relatively low linolenic acid content, but also whichwould have a palmitic acid content similar to that of canola.

Despite all of these prior efforts, there remains a current need forsoybeans having a still further reduced level of linolenic acid. Indeed,it would be considered, from applicants' perspective, a breakthrough tobe able to achieve soybean lines having linolenic acid contents, asdetermined by gas chromatography, of 2.5% or less, much less to be ableto provide soybean lines having linolenic acid contents of 2.0% andless. A soybean line having relatively high stearic acid content and alinolenic acid content of 2.5% or less would be a further breakthrough.It would be yet a further breakthrough to combine, in a soybean line, alow linolenic acid content with a moderately high palmitic acid content.Still additional breakthroughs would thus involve, in a soybean line,the combination of a relatively low linolenic acid and a relatively higholeic acid content and also such a combination with a relatively lowsaturated fatty acid content. Yet another breakthrough would involve thecombination, in a soybean line, of low linolenic and palmitic acidcontents.

SUMMARY OF THE INVENTION

It has been discovered that soybean Glycine max (L). Merr.! varietiesand lines characterized by low linolenic acid concentrations of lessthan about 2.5% of the total fatty acid present may be obtained bycrossing selected mutant soybean strains. More particularly, out ofliterally hundreds of hybridization attempts which have been made overthe years, applicants have discovered a limited number of parent mutantlines which, when crossed, yield a population of seeds characterized byextremely low linolenic acid concentrations. The particular parentmutant lines which have been found to result in the desired lowlinolenic acid trait will be described in the detailed description ofthe invention. Preferably, the present invention provides soybeanshaving a level of linolenic acid less than about 2.2% of the total fattyacid present and, in the most preferred embodiment, the level oflinolenic acid is less than about 1.9% of the total fatty acid.

Progeny having the desired low linolenic acid concentration trait maythen be crossed with other progeny (or with other desired soybean lines)to yield a population of soybean seeds which retain the desired lowlinolenic acid trait. Indeed, under the climatic conditions utilized, aswill be discussed herein, the present invention provides soybean lineshaving a linolenic acid content as low as about 1.2% or so. Selectiveuse of the more desired progeny, it is expected, should provide lineshaving linolenic acid contents even as low as about 1.0% or perhaps evensomewhat less.

It has been also found that, among the progeny characterized by lowlinolenic acid content, some also share the moderately high palmiticacid content desired for some applications. Soybeans having anendogenous linolenic acid content of less than 2.5% by weight and apalmitic acid content of at least 11%, more desirably, 13 or 14% to upto 16% or more, are thus provided.

Still further, it has been discovered that, by crossing progeny havingthe desired low linolenic acid content with a parent having elevatedlevels of stearic acid, a soybean line can be provided which combinesthese characteristics. The stearic acid content is desirably at least20%, more preferably at least 25%, and, even more preferably, at least30% or more. Indeed, stearic acid contents of up to about 32% or so havebeen achieved. The linolenic acid content should be less than 3%,preferably less than about 2.5%, and even more preferably less thanabout 2.2%.

It has further been discovered that soybean lines having not only thedesired low linolenic acid content, but also an oleic acid content of atleast 60% can be obtained. Indeed, it has been discovered that suchsoybean lines can be obtained that also have relatively low palmiticacid and stearic acid contents.

Also, it has been discovered that soybean lines having not only thedesired low linolenic acid content, but also a palmitic acid contentless than about 6% can be obtained. Preferably, the palmitic acidcontent is less than about 5% and even more preferably, less than about4.0%.

If the particular soybean line having the desired low linolenic acidtrait lacks any characteristic desired, such line may be crossed withany cultivar having the characteristic desired. Suitable backcrossingtechniques are known.

A preferred method for producing the low linolenic acid soybeans of thepresent invention involves planting early in the growing season. Thishas been found to make it more likely that the temperature during oildeposition, which temperature affects the linolenic acid content, willbe more suitable to achieving particularly low linolenic acid contents.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Regarding the terminology used herein, the terms "cultivar" and"variety" are used synonymously to refer to those soybean plants whichshare constant characteristics which separate them from other soybeans.The term varieties most often is used to refer to a commercial product.While possessing one or more distinctive traits, a variety like "Pella"or "Weber" is further characterized by a very small overall variationbetween individuals within that variety. A "line, strain or mutant" asdistinguished from a variety most often denotes a group of plants usednon-commercially, for example in plant research. A line, strain ormutant similarly displays very little overall variation betweenindividuals sharing that designation. Unless otherwise indicated, allpercentages refer to the percentage of the individual fatty acid underdiscussion compared to the total fatty acid composition in the soybeanor oil on a weight basis. More accurately, as will be discussedhereinafter, in the gas chromatography methodology, what is reported, asis known, is the methyl ester of the fatty acid. Conversion to the fattyacid itself makes such an extremely minor difference that, for allintents and purposes, the reported values for the methyl ester can betaken as being the value for the free fatty acid itself.

It was originally perceived that the production of a soybean line havinglinolenic acid concentrations of less than 2.5% could be obtained byfirst crossing any moderately low linolenic soybean line (2.9-4.9%) withany high palmitic acid soybean line (greater than 11%). Then, aselection for those progeny producing the lowest levels of linolenicacid was carried out. However, upon further review of the substantialdata which applicants have generated to date, it appears that thisgeneric concept does not hold true.

Indeed, out of the literally hundreds of crosses which have been made,it has been discovered fortuitously that crossing rather select parentsoybean lines provides a population of seeds with the desired lowlinolenic acid trait. More particularly, it has been found that crossingthe mutant line A5 with any of the mutant lines, FA47437EMS, FA47451EMS,FA26315EMS, or FA26591EMS provides a population of soybean seedsexhibiting significantly reduced levels of linolenic acid in comparisonto existing soybean lines. Seeds of each of these mutant lines have beendeposited under the Budapest Treaty in the American Type CultureCollection (ATCC) at 12301 Parklawn Drive, Rockville, Md. 20852, U.S.A.More specifically, 625 seeds of FA47437EMS were deposited on Jan. 10,1989 and have been assigned ATCC Accession No. 40537. 925 additionalseeds of FA47437EMS were deposited on Dec. 19, 1995. 1,575 additionalseeds of FA47437EMS were deposited on April 22, 1996. 2,500 seeds ofFA47451EMS were deposited on Dec. 5, 1995 and have been assigned ATCCAccession No. 97372. 2,500 seeds of FA26315EMS were deposited on Dec. 5,1995 and have been assigned ATCC Accession No. 97367. 550 seeds ofFA26591EMS were deposited on Dec. 5, 1995 and have been assignedAccession No. 97369. 1,950 additional seeds of FA26591EMS were depositedon April 22, 1996. Thus, when planted under similar or the sameconditions, the soybean lines of the present invention will havelinolenic acid contents less than those of A5.

It has been further discovered that the crossing of one of the mutantlines previously identified, viz.--FA26591EMS, with line C1640 resultsin a population of seeds having the desired low linolenic acid trait.C1640 was developed at Purdue University and is a moderately lowlinolenic acid genotype. It is publicly available from James R. Wilcox,Department of Agronomy, Lilly Hall, Purdue University, Lafayette, Ind.47907. 2,500 seeds of C1640 were deposited on Dec. 5, 1995 under theBudapest Treaty in the American Type Culture Collection (ATCC) at 12301Parklawn Drive, Rockville, Md. 20852, U.S.A., and have been assignedAccession No. 97368. While the specific data obtained for the linolenicacid contents was not as low as that obtained when using the mutant lineA5 as a parent, the linolenic acid content was substantially andsignificantly below that which had previously been obtained insofar asapplicants are aware.

Still further, it has been discovered that the crossing of mutant lineFA47451EMS with the mutant line A1937EMS-65 resulted in a population ofseeds having the characteristic low linolenic acid level of the presentinvention. The mutant line A1937EMS-65 will be described in conjunctionwith the Examples. However, in general, this mutant line was obtained bytreating the Asgrow variety A1937 with EMS. While the data obtained wasless desirable than that for progeny resulting from the cross of linesFA26591EMS with the line C1640, the linolenic acid content is consideredto be significantly less than that previously capable of being obtained.

Progeny exhibiting the desired low linolenic acid trait can be crossedwith the parent lines previously identified herein to obtain apopulation of soybean seeds having particularly desirable linolenic acidcontents. As an illustrative example, and as will be seen in thefollowing Examples, the crossing of a parent line (e.g.--FA26591EMS)with progeny (viz.--selected from the crosses of the parent line A5 withthe other mutant lines) provides a population of soybean seeds retainingthe desirable low linolenic acid trait.

Still further, the crossing of selected progeny with other progenylikewise provides a population of soybean seeds having extremely lowlinolenic acid contents. In other words, the low linolenic acid trait ofthe soybean lines of the present invention is heritable. This can beseen from the following Examples.

Crossing to obtain the soybean lines of the present invention can becarried out by any desired hybrid formation technique. Standardhybridization techniques are, of course, well known and may be utilized.As an illustrative example, hybridization techniques are disclosed inFehr, Principles of Cultivar Development, Vol. 1, Theory and Technique,Chapter 13, pp. 156-164, Macmillan Publishing Company, New York, 1987,which hybridization techniques are herein incorporated by reference.

Because the progeny resulting from the crosses identified herein whichprovide a population of seeds having the desired reduced level oflinolenic acid may not themselves exhibit the seed yield and otheragronomic characteristics desired for commercial production, theselection of low linolenic acid offspring by recurring backcrosses witha commercial variety can be conducted until a desirable commercialvariety has been isolated. Backcrossing techniques are known, asdisclosed in Fehr, Principles of Cultivar Development, Vol. 1, Theoryand Technique, Chapter 28, pp. 360-376, the disclosure of which isherein incorporated by reference.

However, as one example, backcrossing using the desired F₂ seedsobtained by natural self-pollination of the F₁ plants could be carriedout as follows:

(1) Plant F₁ seeds obtained by crossing a parent with the desiredreduced linolenic acid trait to the desired commercial cultivar(recurrent parent). Sample F₂ seeds from F₁ plants are analyzed forfatty acid concentration, and seeds with the desired low linolenic acidcontent are planted for backcrossing.

(2) Cross-pollinate the desired commercial cultivar (recurrent parent)with the F₂ plant having the low linolenic acid content.

(3) Plant the BC₁ F₁, seeds and obtain BC₁ F₂ seeds by naturalself-pollination. Sample BC₁ F₂ seeds are analyzed for fatty acidconcentration and those displaying the low linolenic acid trait arebackcrossed to the recurrent parent.

(4) The backcross and selection procedure herein described (Step 3) canbe repeated until lines with the desired low linolenic acid compositionand agronomic performance are recovered. It is believed that four ofthese backcross cycles should serve to transfer the low linolenic acidtrait to the desired cultivar (viz.--recurrent parent), although thenumber of such cycles can be fewer, or more, as is desired. The resultis the production of a soybean line quite similar to the commercialcultivar except having the desired low linolenic acid content.

Any commercial cultivar (recurrent parent) desired may be employed forbackcrossing. Factors such as, for example, seed yield, geographicalarea, and many others, as is known, will generally dictate the cultivarselected from the several hundred commercial cultivars available.

As will be seen in the Examples, progeny from the crosses describedinclude soybean seeds wherein the linolenic acid composition is lessthan 2.5% of the total fatty acid composition, preferably less thanabout 2.2%, and more preferably less than about 1.9%. Surprisingly,soybean lines having as low as about 1.2% linolenic acid and even lowerlevels were obtained. Indeed, since there is no known requirement forlinolenic acid in the soybean seed, it is theoretically possible thatthe methodology disclosed in the present invention may be utilized toyield soybean seeds, products and oil with down to zero linolenic acid.It can be expected that crosses utilizing the more desirable progenyshould be capable of providing lines having linolenic acid contents downto about 1.0% or so.

According to one aspect of this invention, as will be seen from thefollowing Examples, certain of the progeny not only possess the desiredlow linolenic acid trait, but also have the moderately high palmiticacid content preferred for some applications. Thus, as will be seen,soybeans according to the present invention can be provided with lowlinolenic acid content and a palmitic acid content of at least 11%, moredesirably, at least 13 or 14%. Most of such applications desire, it isbelieved, soybeans having palmitic acid contents of 13 or 14% up to 16%or more.

In accordance with a further aspect of the present invention, soybeanlines are provided having not only the desired low linolenic acid traitbut also characterized by an extremely high stearic acid content. Suchsoybean lines may be obtained by crossing progeny having the desired lowlinolenic acid content with the A6 line. The resulting crosses canprovide stearic acid contents even above 30%, up to about 32% or so. Theparticular stearic acid content will be determined by the needs of thespecific application and that will generally be at least about 20% orso. While, in general, the lower the linolenic acid content the better,high stearic lines having linolenic acid contents of as much as 3.0% orso may be useful. More preferably, the linolenic acid contents of suchlines are less than 2.5%, or even 2.2%.

Pursuant to yet another aspect of this invention, soybean lines areprovided having not only the desired low linolenic acid trait but alsocharacterized by an extremely high oleic acid content. Such soybeanlines may be obtained crossing line AX4170-1-1-3 with line AX4174-1-8-9.Parent line AX4170-1-1-3 was obtained by crossing mutant line FA47437EMSwith A5. Parent line AX4174-1-8-9 was obtained from the cross of A5 withmutant line FA26315EMS. Low linolenic soybean lines (viz.--less thanabout 3.0%, preferably less than 2.5 and even lower) may thus beprovided with oleic acid contents in excess of about 60%, preferably inexcess of about 64 or 65% or so. Indeed, progeny exhibiting the desiredhigh oleic acid trait can be crossed with other progeny to provide apopulation of soybean seeds having an extremely high oleic acid content.It can be expected that crosses utilizing the more desirable progenyshould be capable of providing lines having oleic acid contents ofgreater than about 70% or more, perhaps even up to about 75% or perhapsmore.

In accordance with this specific aspect of the present invention, it hasbeen discovered that soybean lines having not only the desired lowlinolenic acid content but also oleic acid contents above.70% may beobtained by crossing line A89-269077 with line AX7689-1-75. Parent lineA89-269077 is an F₂ plant selection from the cross AX4692-123 withHarper 87. Harper 87 is a high yielding cultivar having about 8%linolenic acid. AX4692-123 is a 2% linolenic acid line selected from thecross of AX4170-1-14-4-6 with A84-284033. AX4170-1-14-4-6 is a 2%linolenic acid line selected from the cross of FA47437EMS with A5.A84-284033 is a high-yielding cultivar having about 8% linolenic acid.Parent line AX7689-1-75 was selected from the cross of A89-269041 withAX6002-1-4. A89-269041 is a 2% linolenic acid line whose parentagetraces to the cross of FA47437EMS with A5. AX6002-1-4 is a 50% oleic and2% linolenic acid line obtained from the cross of A87-192020 withAX4585-1-5-3. AX4585-1-5-3 is a line selected from the cross ofFA26591EMS with AX4174, AX4174 being selected from the cross ofFA26315EMS with A5. A87-192020 was selected from the cross ofA83-214072-23-8 with NKS 23-03 A83-214072-23-8 being an F₂ -derived linefrom the cross of Pella with A5.

Yet a further aspect of the present invention provides soybean lineshaving not only the desired low linolenic acid and high oleic acidcontents, but also having an extremely low level of palmitic acid and/orstearic acid. Such soybean lines thus are characterized by an extremelylow saturated fatty acid content.

Such soybean lines may be obtained by crossing AX4585-1-5-3 withAX5152-7. Parent line AX4585-1-5-3 was obtained by crossing mutant lineFA26591EMS with AX4174-1-8-9. AX4174-1-8-9 was obtained from the crossof A5 with mutant line FA26315EMS. Parent line AX5152-7 was obtainedfrom the cross of C1726 with A1937NMU-173.

These low linolenic, high oleic acid content soybean lines are furthercharacterized by a palmitic acid content of no more than about 6.0%and/or a stearic acid content of no more than about 3.5%. It can beexpected that crosses utilizing the more desired progeny should becapable of providing lines having palmitic acid contents of no more than5.5% or 5.0% or perhaps even less and/or a stearic acid content of lessthan about 3.0% or somewhat less.

Further to this aspect of the present invention, it has been discoveredthat soybean lines having the desired low linolenic acid content butalso low palmitic acid content may be obtained by crossing lineA89-269077 with AX7345-2, an F₁ plant of the cross line AX5152-115 withA89-269077. Parent line A89-269077 is the 2.0% linolenic acid cultivarhereinbefore described, and parent line AX5152-115 is described inExample 2 of our copending application, Ser. No. 461,361 hereindescribed, the disclosure regarding line AX5152-115 being hereinincorporated by reference.

These low linolenic and palmitic acid content soybean lines arecharacterized by linolenic acid contents of less than about 3.0%,preferably less than about 2.5%, and even more preferably less thanabout 2.1%. The palmitic acid content is less than about 6.0%,preferably less than about 5.0%, and, more preferably, less than about4.0%. It can be expected that crosses utilizing the more desired progenyshould be capable of providing lines having linolenic acid contents ofno more than about 1.0% and a palmitic acid content of no more than3.0%, perhaps even no more than about 2.5%.

The fatty acid composition was determined by gas chromatography usingthe method as generally outlined in Graef et al. (Crop Science,25:1076-1079, 1985). Thus, in general, the method comprises (1) crushingthe seed sample, (2) putting the crushed sample into a test tube with ahexane solvent and extracting the oil into the hexane, (3) the fattyacids in the oil are converted to their methyl esters using sodiummethoxide and methanol, (4) water is added to inactivate the sodiummethoxide catalyst, and (5) the methyl esters, which float to the top ofthe water-methanol layer, are diluted with hexane and become the samplethat is introduced into the column of the gas chromatography apparatus.

As may be appreciated, this general methodology may be employed andspecific aspects changed to lessen the time needed as desired. Forexample, the stationary phase selected for the columns will dictate thetemperature at which the sample can be introduced.

None of the specifics utilized, e.g.--capillary columns versus packedcolumns, are considered to affect to any appreciable extent the resultsobtained for an analysis. Rather, such specifics affect the timerequired for sample preparation and analysis.

The percentages of the fatty acids set forth herein, unless otherwisedesignated, thus are on a weight basis and refer to the percent of themethyl ester of linolenic or other fatty acid compared to the totalmethyl esters of the fatty acid composition in the sample beinganalyzed. This can also be taken as the weight percent of the free fattyacid itself because the difference between the linolenic acid contentand that of its methyl ester as determined in the gas chromatographytechnique described herein is so minimal as may be ignored, as commonlydone in this field.

The gas chromatographic techniques described herein are routinely usedfor analysis of the fatty acid composition of soybeans. The experimentalerror is considered to be within the range of from about 1 to 5% or so,depending upon the magnitude of the peak. For example, with a relativelylarge peak indicative of an oleic acid content of 50% or so, theexperimental error may be as low as about 1% of the value, viz. -50%±0.5%. At the other extreme, a small peak indicative of a linolenic acidcontent of 2.0% may have an experimental error of about 5% of the value,viz. -2.0% ±0.1%.

As may also be appreciated, the linolenic acid levels of the soybeans ofthe present invention set forth herein were obtained from soybeans grownin Iowa and Puerto Rico. Growth under conditions significantly cooler orwarmer may result in a somewhat altered fatty acid composition.Specifically, early planting is preferred to facilitate development andmaturity of the soybeans during the hot summer growing period therebyproducing soybeans having the lowest level of linolenic acid, asillustrated in Example 18.

The early planting of the soybean seeds, under conditions such asplanting about May 1 in a climate similar to Ames, Iowa, results, it isbelieved, in the lowest levels of linolenic acid. This may be the resultof growing soybeans having an opportunity for development and maturationduring the hot summer months. Such preferred development and maturationmay be accomplished by planting soybeans early in the growing seasonwith maturity reached during the warmest summer months. It isanticipated that these lower levels of linolenic acid in the soybeans ofthe present invention may be caused by a temperature-dependent,rate-limiting enzymatic step in the synthesis of linolenic acid.However, other aspects of plant physiology responding to the highersummer temperature may also be partially responsible for the low levelsof linolenic acid. In Example 18, the A16 and A17 variety planted on May1 had the lowest linolenic acid level found among plantings whichoccurred on May 1, May 15, May 30, and June 15. This is in contrast tothe Century commercial soybean variety which exhibited its highest levelof linolenic acid in the May 1 planting.

A preferred method for producing a substantially homogeneous crop ofsoybeans with linolenic acid content of less than 2.5%, and even morepreferred, less than 2.2% of the total fatty acid composition, involvesthe planting of the soybeans under conditions to insure development andmaturation under high temperatures. Such conditions may be accomplishedby planting as early in the planting season as is physiologicallyacceptable to the growing region. This method for insuring hightemperature development and maturation is accomplished by planting ofsoybean seeds as early in the growing season as is possible to avoiddamaging environmental circumstances, such as frost or freezing weather.For each growing area, the production of low linolenic acid is favored,it is believed, by planting a soybean cultivar which reaches developmentand maturity during the hottest period of the growing season, while sucha hot growing period in the northern hemisphere is best characterized byJuly and August, the months of May, June, September and October may alsohave sufficient or adequate temperatures. The method of producingsoybeans having the low linolenic acid trait may also be accomplished bygerminating and growing seeds in an environmental enclosure capable ofsimulating the conditions similar to Ames, Iowa, from planting about thefirst of May to development and maturation during July and August.

The preferred lower levels of linolenic acid may be achieved byutilizing early maturing varieties for the growing region. By crossingthe low linolenic acid varieties of the present invention with suchearly maturing commercial varieties, the new varieties produced exhibitthe most favorable low linolenic acid levels.

As is thus apparent, the planting and climatic conditions will yieldsoybeans having somewhat varying linolenic acid contents; however, undertypical planting conditions, such as those experienced in Iowa andPuerto Rico, the linolenic acid content of the soybeans of the presentinvention will be below 2.5%, more typically below about 2.2%, and evenmore preferably below about 1.9%. Moreover, when planted under similarconditions, soybeans resulting from the present invention will havelinolenic acid contents well below that resulting from any soybean linepreviously known.

More specifically, the linolenic acid content observed in some instancesfor "selfed" (i.e.--self-pollinated) A5 is below the levels noted in the1983 plantings previously discussed. Indeed, in a few instances, it hasbeen observed that seeds of selfed A5 had linolenic acid contentsdetermined to be as low as 2.5% and down to about 2.4%, perhaps 2.3% orso. However, as is also evident from the following Examples, the soybeanseeds of the present invention, when planted under the same or similarconditions as A5 seeds, uniformly yield soybean plants having endogenouslinolenic acid contents less than that of the A5 plants.

Further, it is possible that planting the soybean seeds of the presentinvention under particularly adverse conditions could result in soybeanplants having linolenic acid contents about 2.5%. Accordingly, as isimplicit herein, the linolenic acid contents set forth herein, refer towhat results from using more typical as opposed to extreme conditions.Again, the use of such extreme conditions will likewise increase evenfurther the linolenic acid content of prior soybean lines, such as A5.

In similar fashion to that of the linolenic acid content, the palmitic,stearic and oleic acid contents of the soybean lines of the presentinvention were obtained from soybeans grown in Iowa and Puerto Rico.Growth under conditions significantly cooler or warmer may result in asomewhat altered fatty acid composition. However, the soybeans of thepresent invention will consistently exhibit the desired palmitic,stearic, and oleic acid contents in comparison to previously knownsoybeans when planted under the same or similar conditions.

Still further, as will be seen in the following Examples, the linolenicacid contents of a particular line may vary somewhat significantly fromgeneration-to-generation. However, as will also be seen, the soybeans ofthe present invention exhibit linolenic acid contents consistently lowerthan any previously known soybeans when planted under the same orsimilar conditions.

Three soybean varieties have been deposited under the Budapest Treaty inthe American Type Culture Collection (ATCC) at 12301 Parklawn Drive,Rockville, Md. 20852, U.S.A. Variety FA47437EMS has been assignedAccession No. 40537; varieties A16 (AX4170-1-1-2) and A17(AX4170-1-15-2) have been respectively assigned Accession No. 40538 andAccession No. 40539. 625 seeds of FA47437EMS were deposited on Jan. 10,1989, 925 additional seeds were deposited on Dec. 19, 1995, and 1,575additional seeds were deposited on Apr. 22, 1996. 625 seeds of A16 weredeposited on Jan. 10, 1989. An additional 1,875 seeds of A16 weredeposited on Dec. 27, 1996. 625 seeds of A17 were deposited on Jan. 10,1989, an additional 1,175 seeds were deposited on Dec. 19, 1995, and anadditional 1,325 seeds were deposited on Apr. 22, 1996. VarietyFA47437EMS was crossed with A5 as described in Example 6 to yield avariety of progeny including A16 and A17. A16 and A17 represent thepreferred embodiments. Both have the desired low linolenic acidcharacteristics. The A16 variety has a more typical palmitic acidcontent, while the A17 variety has a somewhat elevated palmitic acidcontent.

The following Examples are illustrative, but not in limitation, of thepresent invention. The gas chromatography results obtained from theinstrument itself are reported to two decimal points (i.e.--"0.00"). Asreported herein, the fatty acid values are set forth to one decimalpoint. Values of 6 or more in the second decimal point were raised(e.g.--2.29 is reported herein as 2.3), values of 4 or less are ignored(e.g.--2.24 is reported as 2.2), values of 5 are raised if the firstdecimal is odd (e.g.--2.15 is reported as 2.2) and ignored if even(e.g.--2.25 is reported as 2.2).

EXAMPLE 1

This Example describes the preparation of the mutant line FA47437EMS.

Mutant line FA47437EMS was obtained from ethyl methanesulfonate (EMS)treatment of the parent strain FA47437. On June 1, 2,500 seeds of eachparent were soaked in 2.5 L distilled water in a 6 L flask for 9 hoursat room temperature. The flask was aerated for the 9 hours of soaking.The water was drained from the flask, and 2.5 L of 0.1 molar phosphatebuffer at pH 7 and 0.025 molar EMS were added. The seeds were soaked for9 hours, the solution was drained and the seeds were rinsed twice withdistilled water. Treated seeds were placed in containers to preventdrying and transported to the Agricultural Engineering and AgronomyResearch Center near Ames, Iowa. The seeds were planted 2.5 cm deep inmoist soil within 4 hours after the last rinse. The soil was wateredregularly to keep it moist until seedling emergence.

The properties of the mutant seed and their progeny were evaluatedthrough five generations.

A similar number of seeds was harvested from each of the M₁ (firstmutant generation) plants in a population to obtain 2,000 M₂ seeds foreach population. A random sample of 1,000 of the second generation M₂seeds for each population was planted in November at the Iowa StateUniversity--University of Puerto Rico soybean nursery at Isabela, PuertoRico. At least 2,000 M₃ seeds from each population were obtained byharvesting four seeds from each plant. In February, 1,000 M₃ seeds wereplanted in Puerto Rico. At least 2,000 M₄ seeds were obtained byharvesting four seeds from each plant. In June, 1,000 M₄ seeds wereplanted at Ames. Five hundred M₄ plants were harvested individually fromeach population, and a 10-seed sample from each plant was analyzed bygas-liquid chromatography to determine the fatty acid composition. M₅progeny of the mutant plants were evaluated, and the results confirmedthe unique fatty acid composition of the M₄ parent plants.

The mutant strain FA47437EMS will be utilized in making crosses usingstandard hybridization procedures to prepare soybeans having the lowlinolenic acid trait characteristic of the present invention.

EXAMPLE 2

A parent mutant line FA47451EMS was prepared using the same procedure asdescribed in Example 1, except that FA47451 was used in place ofFA47437.

EXAMPLE 3

A parent mutant line FA26315EMS was prepared using the same procedure asdescribed in Example 1, except that FA26315 was used in place ofFA47437.

EXAMPLE 4

A parent mutant line FA26591EMS was prepared using the same procedure asdescribed in Example 1, except that FA26591 was used in place ofFA47437.

EXAMPLE 5

A parent mutant line A1937EMS-65 was prepared using the same procedureas described in Example 1, except that Asgrow A1937 was used in place ofFA47437. 2,500 seeds of a1937EMS-65 were deposited on Dec. 5, 1995 underthe Budapest Treaty in the American Type Culture Collection (ATCC) at12301 Parklawn Drive, Rockville, Md. 20852, U.S.A., and have beenassigned Accession No. 97370.

EXAMPLE 6

This Example describes the crossing of parent A5 with the mutant lineFA47437EMS prepared as described in Example 1 to obtain soybeans of thepresent invention. The hybrid F_(l) seeds obtained from the cross weredesignated AX4170.

F₁ plants of the cross AX4170 were grown in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₂ seeds were obtained by natural self-pollination. Each F₁ plant washarvested individually, and the F₂ seeds of each were maintained asseparate subpopulations of the cross.

One hundred F₂ seeds from the F₁ plant designated AX4170-1 were plantedin the Iowa State University--University of Puerto Rico nursery atIsabela, Puerto Rico. F₃ seeds were obtained by naturalself-pollination. Each F₂ plant was harvested individually.

A 10-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. An analysis of individual splitseeds from the F₂ plants and parent lines was also made. Two F₂ plantsdesignated AX4170-1-1 and AX4170-1-15 were selected with a linolenicacid percentage lower than that of either parent and lower than thatpreviously described for soybeans.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table I, thevalues set forth being the mean of the split seeds rather than those ofthe 10-seed bulk sample since the split seed values are considered to bemore representative:

                  TABLE I                                                         ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4170-1-1 13.8     3.2     42.0  39.2  1.9                                   AX4170-1-15                                                                              17.0     2.8     28.3  49.6  2.4                                   FA47437EMS 16.8     3.8     32.2  42.4  4.7                                   A5         9.1      2.8     58.4  27.0  2.8                                   ______________________________________                                    

F₃ seeds from the F₂ parent plants AX4170-1-1 and AX4170-1-15 wereplanted in Puerto Rico. Ten individual F₃ plants were harvested fromeach of these F₂ parent plants. The fatty acid composition of the F₃plants AX4170-1-1-2 and AX4170-1-15-2 was determined and is set forth inTable II:

                  TABLE II                                                        ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4170-1-1-2                                                                             11.0     4.5     34.0  48.1  2.4                                   AX4170-1-15-2                                                                            16.4     3.6     28.3  49.5  2.2                                   FA47437EMS 17.7     4.1     23.7  48.8  5.7                                   A5         10.0     3.6     44.5  38.4  3.4                                   ______________________________________                                    

F₄ seeds from individual F₃ parent plants AX4170-1-1-2 and AX4170-1-15-2were planted at the Agricultural Engineering and Agronomy ResearchCenter. Individual F₄ plants were harvested from each F₃ parent plant.The fatty acid composition of the F₄ generation was determined and isset forth in Table III:

                  TABLE III                                                       ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4170-1-1-2                                                                             10.4     4.6     33.2  49.8  2.0                                   AX4170-1-15-2                                                                            15.1     3.8     39.1  40.0  1.9                                   A5         10.1     3.4     38.2  44.8  3.4                                   ______________________________________                                         FA47437EMS was not grown in the test                                     

Thus, as has been seen, the cross of the two mutant lines resulted in apopulation of soybeans having extremely low linolenic acid contents. Itis considered that the F₂, F₃ and F₄ plant data confirm that stablegenotypes were developed having the lowest linolenic acid percentagesever reported for soybeans insofar as applicants are aware.

EXAMPLE 7

This Example describes the crossing of parent line A5 with the mutantline FA47451EMS prepared as described in Example 2 to obtain soybeanlines of the present invention. The hybrid F₁ seeds obtained from thecross were designated AX4172.

F₁ plants were grown as described in Example 6. F₂ seeds were obtainedby natural self-pollination. Each F₁ plant was harvested individually,and the F₂ seeds of each were maintained as separate subpopulations ofthe cross.

One hundred F₂ seeds from the F₁ plant designated AX4172-1 were plantedas described in Example 6. F₃ seeds were obtained by naturalself-pollination. Each F₂ plant was harvested individually.

A 10-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. Two F₂ plants designatedAX4172-1-24 and AX4172-1-35 were selected with a linolenic acid contentbeing lower than that of either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table IV:

                  TABLE IV                                                        ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4172-1-24                                                                              8.7      2.8     62.4  24.1  2.0                                   AX4172-1-35                                                                              14.5     1.8     52.3  29.3  2.1                                   FA47451EMS 17.0     3.8     31.1  42.4  5.7                                   A5         9.5      2.9     58.1  26.6  2.9                                   ______________________________________                                    

F₃ seeds from the F₂ parent plants AX4172-1-24 and AX4712-1-35 wereplanted in Puerto Rico. Ten individual F₃ plants were harvested fromeach of these F₂ parent plants. The fatty acid composition of the F₃plants AX4172-1-24-3 and AX4172-1-35-8 was determined and is set forthin Table V:

                  TABLE V                                                         ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4172-1-24-3                                                                            9.6      4.3     39.7  43.1  3.3                                   AX4172-1-35-8                                                                            16.8     3.3     30.5  46.0  3.3                                   FA47451EMS 16.4     4.2     21.2  50.5  7.7                                   A5         9.1      3.5     52.0  32.0  3.4                                   ______________________________________                                    

F₄ seeds from the individual F₃ parent plants were planted at theAgricultural Engineering and Agronomy Research Center at Ames, Iowa.Individual plants were harvested from each F₃ parent plant. The fattyacid composition of the F₄ generation was determined and is set forth inTable VI:

                  TABLE VI                                                        ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4172-1-24-3                                                                            10.4     4.0     43.4  39.6  2.5                                   AX4172-1-35-8                                                                            16.0     3.6     42.7  34.9  2.8                                   FA47451EMS 15.6     4.9     34.8  40.9  3.8                                   A5         10.0     3.1     39.3  44.1  3.5                                   ______________________________________                                    

EXAMPLE 8

This Example describes the crossing of parent line A5 with the mutantline FA26315EMS prepared as described in Example 3. The hybrid F₁ seedsobtained from the cross were designated AX4174.

F₁ plants were grown as described in Example 6. F₂ seeds were obtainedby natural self-pollination. Each F₁ plant was harvested individually,and the F₂ seeds of each were maintained as separate subpopulations ofthe cross.

One hundred F₂ seeds from the F₁ plant were planted as in Example 6. F₃seeds were obtained by natural self-pollination. Each F₂ plant washarvested individually.

A 10-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. Two F₂ plants designatedAX4174-2-6 and AX4174-5-8 were selected with a linolenic acid contentbeing lower than that of either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table VII:

                  TABLE VII                                                       ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4174-2-6 11.6     1.9     63.8  20.5  2.1                                   AX4174-5-8 14.9     1.2     47.8  33.9  2.2                                   FA26315EMS 13.8     1.9     47.0  33.8  3.6                                   A5         9.3      2.7     55.6  27.6  2.8                                   ______________________________________                                    

F₃ seeds from the F₂ parent plants AX4174-2-6 and AX4174-5-8 wereplanted in Puerto Rico. Ten individual F₃ plants were harvested fromeach of these F₂ parent plants. The fatty acid composition of the F₃plants AX4174-2-6 -4 and AX4174-5-8-4 was determined and is set forth inTable VIII:

                  TABLE VIII                                                      ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4174-2-6-4                                                                             10.0     3.7     36.4  46.9  3.0                                   AX4174-5-8-4                                                                             16.1     3.6     32.4  44.6  3.2                                   FA26315EMS 16.0     5.5     31.2  42.2  5.0                                   A5         10.0     3.1     39.3  44.1  3.5                                   ______________________________________                                    

EXAMPLE 9

This Example describes the crossing of the parent line A5 with themutant line FA26591EMS prepared as described in Example 4 to obtain thesoybean lines of the present invention. The hybrid F₁ seeds obtainedfrom the cross were designated AX4416.

F₁ plants of the cross AX4416 were grown in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₂ seeds were obtained by natural self-pollination. Each F₁ plant washarvested individually, and the F₂ seeds of each were maintained asseparate subpopulations of the cross.

A total of 200 F₂ seeds from the cross were planted in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₃ seeds were obtained by natural self-pollination. One hundred F₂plants were harvested individually.

A 10-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. The F₂ plant designatedAX4416-7-2 was selected with a linolenic acid percentage lower than thatof either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table IX:

                  TABLE IX                                                        ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4416-7-2 9.8      3.4     54.1  30.7  2.0                                   FA26591EMS 9.0      3.9     44.7  38.0  4.4                                   A5         9.7      2.7     51.6  33.0  3.0                                   ______________________________________                                    

F₃ seeds from the F₂ parent plant AX4416-7-2 were planted at Ames, Iowa.Ten individual F₃ plants were harvested from the F₃ parent plants. Thefatty acid composition of the F₃ plant AX4416-7-2-2 was determined andis set forth below in Table X:

                  TABLE X                                                         ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4416-7-2-2                                                                             10.4     5.0     28.9  52.5  3.2                                   FA26591EMS 9.9      7.2     25.0  49.3  8.6                                   A5         9.4      4.6     28.3  52.3  5.4                                   ______________________________________                                    

F₄ seeds from the F₃ parent plant AX4416-7-2-2 were planted at Ames,Iowa. Ten individual F₄ plants were harvested from the F₃ parent plants.The fatty acid composition of the F₄ generation was determined and isset forth in Table XI:

                  TABLE XI                                                        ______________________________________                                                 Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                            Linolenic                                        Acid     Acid    Acid  Acid  Acid                                  Seed Identification                                                                      (16:0)   (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                ______________________________________                                        AX4416-7-2-2                                                                             10.1     4.9     56.4  26.9  1.7                                   FA26591EMS 10.7     6.3     36.9  42.4  3.7                                   A5         11.6     4.5     22.4  58.0  3.6                                   ______________________________________                                    

EXAMPLE 10

This Example describes the crossing of line C1640 with the mutant lineFA26591EMS, one of the parents used in Example 9. The hybrid F₁ seedsobtained from the cross were designated AX4417.

F₁ plants of the cross AX4417 were grown in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₂ seeds were obtained by natural self-pollination. Each F₁ plant washarvested individually, and the F₂ seeds of each were maintained asseparate subpopulations of the cross.

A total of 200 F₂ seeds from the cross were planted in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₃ seeds were obtained by natural self-pollination. One hundred F₂plants were harvested individually.

A 10-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. The F₂ plant designatedAX4417-2-16 was selected with a linolenic acid percentage lower thanthat of either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table XII:

                  TABLE XII                                                       ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4417-2-16                                                                              10.7    4.2     49.5  33.2  2.3                                    FA26591EMS 10.0    4.2     41.4  44.3  4.5                                    C1640      10.8    3.8     24.8  56.6  4.0                                    ______________________________________                                    

F₃ seeds from the F₂ parent plant AX441-2-16 were planted at Ames, Iowa.Ten individual F₃ plants were harvested from the F₂ parent plants. Thefatty acid composition of the F₃ plant AX4417-2-16-5 was determined andis set forth below in Table XIII:

                  TABLE XIII                                                      ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4417-2-16-5                                                                            9.9     5.4     24.1  57.2  3.5                                    FA26591EMS 9.5     6.3     26.7  49.3  8.1                                    C1640      9.3     4.0     21.3  60.5  4.9                                    ______________________________________                                    

F₄ seeds from the F₃ parent plant AX4417-2-16-5 were planted at Ames,Iowa. Ten individual F₄ plants were harvested from the F₃ parent plants.The fatty acid composition of the F₄ generation was determined and isset forth in Table XIV:

                  TABLE XIV                                                       ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4417-2-16-5                                                                            11.6    5.6     31.6  48.9  2.4                                    FA26591EMS 10.9    7.6     29.5  47.3  4.7                                    C1640      10.5    4.2     23.6  57.9  3.8                                    ______________________________________                                    

EXAMPLE 11

This Example describes the crossing of the mutant line A1937EMS-65prepared as described in Example 5 with the parent line FA47451EMS, oneof the parent lines used in the cross prepared in Example 7. The hybridF₁ seeds obtained from the cross were designated AX4889.

F₁ plants from the cross AX4889 were grown in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₂ seeds were obtained by natural self-pollination. Each F₁ plant washarvested individually, and the F₂ seeds of each were maintained asseparate subpopulations of the cross.

F₂ seeds from each of these F₁ plants designated AX4889-1, AX4889-2 andAX4889-3 were planted in the Iowa State University--University of PuertoRico nursery at Isabela, Puerto Rico. Seven F₂ plants were harvestedindividually from each of the three subpopulations.

A 10-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. F₂ plants designated AX4889-2-6and AX4889-3-1 were selected as having a linolenic acid content lowerthan that of either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table XV:

                  TABLE XV                                                        ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4889-2-6 14.4    4.2     28.4  50.6  2.4                                    AX4889-3-1 12.4    4.2     19.8  61.1  2.5                                    FA47451EMS 16.4    4.1     23.3  51.2  4.9                                    A1937EMS-65                                                                              12.4    4.1     21.6  57.8  4.1                                    ______________________________________                                    

EXAMPLE 12

This Example describes the crossing of one of the parent lines used inExample 9 (i.e.--FA26591EMS) with progeny from the cross obtained inExample 6 (the progeny being designated as AX4170-1-1). The hybrid F₁seeds obtained from the crosses were designated AX4561-AX4570.

F₁ plants of AX4561-AX4570 were grown in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₂ seeds were Obtained by natural self-pollination. Each F₁ plant washarvested individually, and the F₂ seeds of each were maintained asseparate subpopulations.

A total of 210 F₂ seeds from the populations AX4561-AX4570 were plantedin the Iowa State University--University of Puerto Rico nursery atIsabela, Puerto Rico. F₃ seeds were obtained by naturalself-pollination. Approximately 150 F₂ plants were harvestedindividually.

A 5-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. Two F₂ plants designatedAX4561-2-6 and AX4568-1-7 were selected with a linolenic acid contentbeing lower than that of either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table XVI:

                  TABLE XVI                                                       ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4561-2-6 8.8     3.8     59.2  26.4  1.7                                    AX4568-1-7 11.2    3.8     59.2  25.0  1.7                                    AX4170-1-1 16.5    4.9     28.5  47.9  2.2                                    FA26591EMS 8.6     4.9     48.4  35.0  3.1                                    ______________________________________                                    

F₃ seeds from the F₂ plants AX4561-2-6 and AX4568-1-7 were grown inPuerto Rico. Individual F₃ plants were harvested. The fatty acidcomposition of the F₃ plants AX4561-2-6-1 and AX4568-1-7-5 wasdetermined and is set forth in Table XVII:

                  TABLE XVII                                                      ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4561-2-6-1                                                                             9.2     3.4     65.0  21.1  1.3                                    AX4568-1-7-5                                                                             12.3    4.2     59.3  22.8  1.4                                    AX4170-1-1 15.3    3.7     37.9  41.3  1.8                                    FA26591EMS 9.1     4.3     58.2  25.5  2.9                                    ______________________________________                                    

F₄ seeds from the individual F₃ parent plants were planted at theAgricultural Engineering and Agronomy Research Center at Ames, Iowa.Individual plants were harvested from each F₃ parent plant. The fattyacid composition of the F₄ generation was determined and is set forth inTable XVIII:

                  TABLE XVIII                                                     ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18.1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4561-2-6-1                                                                             9.3     5.2     50.2  33.4  1.8                                    AX4568-1-7-5                                                                             12.1    5.8     33.2  46.9  1.9                                    AX4170-1-1 15.2    4.8     37.8  40.3  2.0                                    FA26591EMS 10.0    4.3     44.2  38.0  3.4                                    ______________________________________                                    

EXAMPLE 13

This Example describes the crossing of parent FA26591EMS used in Example9 and progeny from the soybeans obtained in Example 7 (the progeny beingdesignated AX4172-1-24-2). The hybrid F₁ seeds obtained from the crosswere designated AX4571.

F₁ plants of AX4571 were grown in the Iowa State University--Universityof Puerto Rico nursery at Isabela, Puerto Rico. F₂ seeds were obtainedby natural self-pollination. Each F₁ plant was harvested individually,and the F₂ seeds of each were maintained as separate subpopulations.

A total of 30 F₂ seeds from the population AX4571 were planted in theIowa State University--University of Puerto Rico nursery at Isabela,Puerto Rico. F₃ seeds were obtained by natural self-pollination.Approximately 20 F₂ plants were harvested individually.

A 5-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. One F₂ plant designatedAX4571-1-2 was selected with a linolenic acid content being lower thanthat of either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table XIX:

                  TABLE XIX                                                       ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4571-1-2 8.2     5.0     59.6  24.9  2.3                                    AX4172-1-24-2                                                                            10.5    4.4     38.2  42.8  4.1                                    FA26591EMS 8.6     4.9     48.4  35.0  3.1                                    ______________________________________                                    

F₃ seeds from the F₂ plant AX4571-1-2 was grown in Puerto Rico.Individual F₃ plants were harvested. The fatty acid composition of theF₃ plant AX4571-1-2-1 was determined and is set forth in Table XX:

                  TABLE XX                                                        ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4571-1-2-1                                                                             8.2     4.3     66.8  19.4  1.3                                    AX4172-1-24-2                                                                            8.8     3.2     54.2  31.4  2.8                                    FA26591EMS 9.1     4.3     58.2  25.5  2.9                                    ______________________________________                                    

F₄ seeds from the individual F₃ parent plants were planted at theAgricultural Engineering and Agronomy Research Center at Ames, Iowa.Individual plants were harvested from each F₃ parent plant. The fattyacid composition of the F₄ generation was determined and is set forth inTable XXI:

                  TABLE XXI                                                       ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4571-1-2-1                                                                             8.9     6.1     45.5  37.4  2.1                                    AX4172-1-24-2                                                                            9.1     5.9     40.6  41.5  2.9                                    FA26591EMS 10.0    4.3     44.2  38.0  3.4                                    ______________________________________                                    

EXAMPLE 14

This Example describes the crossing of the parent FA26591EMS withprogeny obtained from the cross described in Example 8 (the progenybeing designated as AX4174-1-8-9). The hybrid F₁ seeds obtained from thecrosses were designated AX4572-AX4588.

F₁ plants of AX4572-AX4588 were grown in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₂ seeds were obtained by natural self-pollination. Each F₁ plant washarvested individually, and the F₂ seeds of each were maintained asseparate subpopulations.

A total of 270 F₂ seeds from the populations AX4572-AX4588 were plantedin the Iowa State University--University of Puerto Rico nursery atIsabela, Puerto Rico. F₃ seeds were obtained by naturalself-pollination. Approximately 180 F₂ plants were harvestedindividually.

A 5-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. Two F₂ plants designatedAX4585-1-5 and AX4586-1-2 were selected with a linolenic acid contentbeing lower than that of either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table XXII:

                  TABLE XXII                                                      ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4585-1-5 9.0     3.6     50.1  35.0  2.2                                    AX4586-1-2 9.1     4.1     55.9  28.9  2.0                                    AX4174-1-8-9                                                                             16.1    3.1     40.7  36.9  3.2                                    FA26591EMS 8.6     4.9     48.4  35.0  3.1                                    ______________________________________                                    

F₃ seeds from the F₂ plants AX4585-1-5 and AX4586-1-2 were grown inPuerto Rico. Individual F₃ plants were harvested. The fatty acidcomposition of the F₃ plants AX4585-1-5-3 and AX4586-1-2-1 wasdetermined and is set forth in Table XXIII:

                  TABLE XXIII                                                     ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4585-1-5-3                                                                             8.4     3.3     68.0  18.9  1.3                                    AX4586-1-2-1                                                                             8.3     3.5     70.7  16.2  1.4                                    AX4174-1-8-9                                                                             13.9    2.7     62.2  18.9  2.3                                    FA26591EMS 9.1     4.3     58.2  25.5  2.9                                    ______________________________________                                    

F₄ seeds from the individual F₃ parent plants were planted at theAgricultural Engineering and Agronomy Research Center at Ames, Iowa.Individual plants were harvested from each F₃ parent plant. The fattyacid composition of the F₄ generation was determined and is set forth inTable XXIV:

                  TABLE XXIV                                                      ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic Linoleic                                                                            Linolenic                                         Acid    Acid    Acid  Acid  Acid                                   Seed Identification                                                                      (16:0)  (18:0)  (18:1)                                                                              (18:2)                                                                              (18:3)                                 ______________________________________                                        AX4585-1-5-3                                                                             8.8     4.0     55.8  29.4  2.0                                    AX4586-1-2-1                                                                             9.7     4.4     50.8  33.4  1.8                                    AX4174-1-8-9                                                                             16.6    5.3     39.2  35.8  3.1                                    FA26591EMS 10.0    4.3     44.2  38.0  3.4                                    ______________________________________                                    

EXAMPLE 15

This Example describes the crossing of progeny obtained as described inExample 6 with progeny obtained as described in Example 8 (the progenybeing designated as AX4170-1-1 and AX4174-1-8-9, respectively). Thehybrid F₁ seeds obtained from the crosses were designated AX4605-AX4613.

F₁ plants of AX4605-AX4613 were grown in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₂ seeds were obtained by natural self-pollination. Each F₁ plant washarvested individually, and the F₂ seeds of each were maintained asseparate subpopulations.

A total of 210 F₂ seeds from the populations AX4605-AX4613 were plantedin the Iowa State University--University of Puerto Rico nursery atIsabela, Puerto Rico. F₃ seeds were obtained by naturalself-pollination. Approximately 170 F₂ plants were harvestedindividually.

A 5-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. Two F₂ plants designatedAX4611-1-14 and AX4612-1-12 were selected with a linolenic acid contentbeing lower than that of either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table XXV:

                  TABLE XXV                                                       ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX4611-1-14                                                                              16.7    3.7     40.4   37.1  2.0                                   AX4612-1-12                                                                              11.8    3.6     43.9   38.7  2.0                                   AX4170-1-1 16.5    4.9     28.5   47.9  2.2                                   AX4174-1-8-9                                                                             16.1    3.1     40.7   36.9  3.2                                   ______________________________________                                    

F₃ seeds from the F₂ plants AX4611-1-14 and AX4612-1-12 were grown inPuerto Rico. Individual F₃ plants were harvested. The fatty acidcomposition of the F₃ plants AX4611-1-14-3 and AX4612-1-12-2 wasdetermined and is set forth in Table XXVI:

                  TABLE XXVI                                                      ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX4611-1-14-3                                                                            13.7    2.8     59.0   23.0  1.4                                   AX4612-1-12-2                                                                            12.2    2.5     64.6   20.0  1.4                                   AX4170-1-1 15.3    3.7     37.9   41.3  1.8                                   AX4174-1-8-9                                                                             13.9    2.7     62.2   18.9  2.3                                   ______________________________________                                    

F₄ seeds from the individual F₃ parent plants were planted at theAgricultural Engineering and Agronomy Research Center at Ames, Iowa.Individual plants were harvested from each F₃ parent plant. The fattyacid composition of the F₄ generation was determined and is set forth inTable XXVII:

                  TABLE XXVII                                                     ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX4611-1-14-3                                                                            16.1    5.4     34.4   42.2  1.9                                   AX4612-1-12-2                                                                            14.6    5.0     38.4   40.1  1.9                                   AX4170-1-1 15.2    4.8     37.8   40.3  2.0                                   AX4174-1-8-9                                                                             16.6    5.3     39.2   35.8  3.1                                   ______________________________________                                    

EXAMPLE 16

This Example describes the crossing of the progeny obtained from Example7 (designated as AX4172-1-24-2) with progeny obtained as described inExample 8 (designated as AX4174-1-2-3) to obtain soybean lines inaccordance with the present invention. The hybrid F_(l) seeds obtainedfrom the cross were designated as AX4591-AX4604.

F₁ plants of AX4591-AX4604 were grown in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₂ seeds were obtained by natural self-pollination. Each F₁ plant washarvested individually, and the F₂ seeds of each were maintained asseparate subpopulations.

A total of 500 F₂ seeds from the populations AX4591-AX4604 were plantedin the Iowa State University--University of Puerto Rico nursery atIsabela, Puerto Rico. F₃ seeds were obtained by naturalself-pollination. Approximately 425 F₂ plants were harvestedindividually.

A 5-seed sample from each F₂ plant was analyzed by gas-liquidchromatography at Iowa State University. Two F₂ plants designatedAX4592-1-28 and AX4597-1-36 were selected with a linolenic acid contentbeing lower than that of either parent.

The fatty acid composition of the soybeans of the present invention aswell as that of the parent mutant lines is set forth in Table XXVIII:

                  TABLE XXVIII                                                    ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX4592-1-28                                                                              10.6    4.0     54.4   28.4  2.7                                   AX4597-1-36                                                                               9.3    3.4     61.4   23.5  2.3                                   AX4172-1-24-2                                                                            10.5    4.4     38.2   42.8  4.1                                   AX4174-1-2-3                                                                             16.6    3.6     29.4   47.1  3.3                                   ______________________________________                                    

F₃ seeds from the F₂ plants AX4592-1-28 and AX4597-1-36 were grown inPuerto Rico. Individual F₃ plants were harvested. The fatty acidcomposition of the F₃ plants AX4592-1-28-2 and AX4597-1-36-3 wasdetermined and is set forth in Table XXIX:

                  TABLE XXIX                                                      ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX4592-1-28-2                                                                            8.8     3.4     70.3   15.9  1.7                                   AX4597-1-36-3                                                                            7.7     3.2     71.2   15.9  2.1                                   AX4172-1-24-2                                                                            8.8     3.2     54.2   31.4  2.3                                   AX4174-1-2-3                                                                             15.1    2.9     45.8   33.7  2.6                                   ______________________________________                                    

F₄ seeds from the individual F₃ parent plants were planted at theAgricultural Engineering and Agronomy Research Center at Ames, Iowa.Individual plants were harvested from each F₃ parent plant. The fattyacid composition of the F₄ generation was determined and is set forth inTable XXX:

                  TABLE XXX                                                       ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX4592-1-28-2                                                                            9.1     5.4     43.8   39.3  2.5                                   AX4597-1-36-3                                                                            9.0     4.6     48.4   35.6  2.4                                   AX4172-1-24-2                                                                            9.1     5.9     40.6   41.5  2.9                                   AX4174-1-2-3                                                                             15.1    4.1     43.6   34.4  2.9                                   ______________________________________                                    

EXAMPLE 17

This Example reflects the heritability of the low linolenic acid traitin the lines A16 and A17, viz.--progeny produced from the crossdescribed in Example 6.

A16 and A17 seeds were allowed to self-pollinate and were also crossedwith the following parents: Century 84 (a commercial cultivar), C1640and their parents (viz.--A5 and FA47437EMS). These were planted in Ames,Iowa, in 1988.

The mean linolenic acid percentage of the self-pollinated seeds and thehybrid seeds from crosses between A16 and the four other genotypes wereobtained and are summarized in Table XXXI:

                  TABLE XXXI                                                      ______________________________________                                                   Parent Mated With A16                                                           Century                                                          Entry        84       C1640   A5    FA47437EMS                                ______________________________________                                        Parent Mean Linolenic                                                         Acid Content                                                                  A16          2.1*     1.9*    2.3*  1.7*                                      Other Parent 7.6      3.2     2.9   3.7                                       Hybrid Seed Mean Lino-                                                        lenic Acid Content                                                            One Cross    3.7*     2.4*    2.5 ns                                                                              2.6 ns                                    Reciprocal Cross                                                                           5.2      3.0     2.4   2.9                                       (0.05 - Least Significant                                                                  0.45     0.25    0.19  0.44                                      Difference)                                                                   ______________________________________                                         *Selfed seed of the two parents or hybrid seed from the reciprocal crosse     were significantly different at the 0.05 probability level.                   ns Hybrid seeds from reciprocal crosses were not significantly different.

The mean linolenic acid percentage of the self-pollinated seeds and thehybrid seeds from crosses between A17 and the other four genotypes wereobtained and are summarized in Table XXXII:

                  TABLE XXXII                                                     ______________________________________                                                   Parent Mated With A17                                                           Century                                                          Entry        84       C1640   A5    FA47437EMS                                ______________________________________                                        Parent Mean Linolenic                                                         Acid Content                                                                  A17          2.2*     2.1*    1.6*  1.8*                                      Other Parent 8.3      3.6     2.6   4.7                                       Hybrid Seed Mean Lino-                                                        lenic Acid Content                                                            One Cross    3.7*     2.3*    2.2 ns                                                                              3.2 ns                                    Reciprocal Cross                                                                           5.1      3.0     2.2   3.0                                       (0.05 - Least Significant                                                                  0.79     0.12    0.22  0.70                                      Difference)                                                                   ______________________________________                                         *Selfed seed of the two parents or hybrid seed from the reciprocal crosse     were significantly different at the 0.05 probability level.                   ns Hybrid seeds from reciprocal crosses were not significantly different.

The Tables XXXI and XXXII support the conclusion that there is a partialmaternal effect expressed when A16 and A17 are crossed with Century 84and C1640 but not when these soybean lines are crossed with theirparents. The partial maternal effect means that the genotype of theplant has a partial influence on the linolenic acid percentage of theseed produced on it, and the genotype of the seed also has a partialinfluence on its linolenic acid percentage. The absence of a maternaleffect would indicate that the genotype of the seed entirely controlsits linolenic acid percentage.

With either partial or no maternal inheritance, it is possible to selectamong F₂ seeds on F₁ plants for linolenic acid percentage. This speedsup the transfer of genes from one parent to another by carrying outbackcrossing techniques.

The analyses of individual F₂ seed from the crosses A16 with Century 84and A17 with Century 84 were conducted with seeds harvested in January,1989, in Puerto Rico. The mean linolenic acid content was 1.9% for A16,2.1% for A17, and 8.3% for Century 84. Seven out of 154 (4.5%) of the F₂seeds had a linolenic acid content of less than 2.5%. Based upon thisdata, it can be concluded that the low linolenic acid is an inheritedtrait, the low percentage obtained indicates that multiple genes controlthe trait and that, in a backcrossing program, selection should bepracticed among F₂ seeds or plants; and plants grown from those with lowlinolenic acid should be backcrossed to the recurrent parent.

Backcrossing can be used successfully to transfer the low linolenic acidgenes from A16 and A17 to high-yielding cultivars like Century 84. Thepercentage of F₂ seeds in each backcross generation with less than 2.5%linolenic acid has been about 4%. This is an adequate percentage ofuseful segregates to use in a backcrossing program.

EXAMPLE 18

This Example determines the fatty acid composition of five soybeangenotypes to evaluate the effect of varied planting dates.

As previously indicated, A16 is the same as AX4170-1-1-2; and A17 is thesame as AX4170-1-15-2. The soybean variety C1640 is a moderately lowlinolenic acid genotype developed by USDA/Purdue and is publiclyavailable. C1640 was used as a control line along with the commercialsoybean cultivar, Century, from which C1640 was obtained by chemicalmutagenesis.

The fatty acid composition of the seed oil of five soybean genotypes isillustrated in Table XXXIII. The five varieties were planted in thefield on May 1, May 15, May 30 and June 15 at Iowa State University,Ames, Iowa. Three replications of a randomized complete block design foreach variety were used with a split-plot arrangement of genotypes aswhole plots and planting dates as subplots.

                  TABLE XXXIII                                                    ______________________________________                                        Planting Date                                                                          Fatty Acid Percentages                                               Genotype Palmitic Stearic  Oleic Linoleic                                                                             Linolenic                             ______________________________________                                        May 1                                                                         A16      11.2     6.4      37.6  42.2   1.9                                   A17      15.3     5.5      35.4  41.0   2.0                                   A5       9.8      5.5      47.7  33.6   2.8                                   C1640    11.3     4.3      25.4  55.2   3.4                                   Century  11.1     4.3      22.6  54.9   6.7                                   May 15                                                                        A16      11.8     6.2      35.0  44.3   2.1                                   A17      15.5     5.5      34.3  41.7   2.0                                   A5       9.9      5.4      50.1  31.4   2.6                                   C1640    11.6     4.3      25.2  55.4   3.4                                   Century  11.4     4.1      24.6  53.4   6.3                                   May 30                                                                        A16      12.0     5.9      31.8  47.6   2.2                                   A17      16.6     5.1      30.9  44.0   2.4                                   A5       10.8     5.6      45.7  34.3   3.0                                   C1640    11.1     4.5      24.9  55.2   4.0                                   Century  10.9     4.4      25.7  52.4   6.4                                   June 15                                                                       A16      12.1     6.0      27.9  51.1   2.4                                   A17      16.6     4.7      29.2  46.2   2.3                                   A5       11.2     5.0      37.0  43.2   3.1                                   C1640    10.4     5.2      23.2  57.0   3.9                                   Century  10.3     5.1      23.4  54.3   6.5                                   LSD                                                                           (0.05)   0.38     0.38     3.54  3.27   0.49                                  ______________________________________                                    

These results indicate that A16 and A17 reproducibly exhibit the lowlinolenic acid phenotype. The later in the season the soybeans wereplanted, the higher the linolenic acid concentration. For example, theA16 planted on May 1 at Ames, Iowa, had 1.9% linolenic acid; the May 15planting had 2.1% linolenic acid; the May 30 planting had 2.2% linolenicacid; and the June 15 planting had 2.4% linolenic acid. The earlier inthe season the planting is made, the lower the linolenic acid levelexhibited. However, in all four plantings, the level exhibited was lessthan 2.5% linolenic acid and was significantly less than the linolenicacid content of A5.

The development and maturation under high temperature conditions of thesoybeans of the present invention results in lower levels of linolenicacid, as illustrated in Table XXXIII. Table XXXIV illustrates thetemperature and day length data corresponding to five soybean genotypesdescribed in Table XXXIII. The temperature and day length data for A16,A17, A5, C1640 and Century were recorded for plantings in the field onMay 1, May 15, May 30 and June 15 at Iowa State University in Ames,Iowa. R1 is the stage of plant development when there is one open flowerat any node on the main stem. R5 is when there is a seed 3 mm long in apod at one of the four uppermost nodes on the main stem with a fullydeveloped leaf. R7 is when there is one normal pod on the main stem thathas reached its mature pod color. The final development and maturationduring the hotter summer months resulted in the lowest levels oflinolenic acid detected among the four plantings (Table XXXIII).

                                      TABLE XXXIV                                 __________________________________________________________________________                          R1 to R7       R5 to R7                                        Reproductive Stages                                                                              Avg. Daily                                                                          Avg. Day Avg. Daily                                                                          Avg. Day                       Planting Date                                                                        R1   R5   R7   No. of                                                                            High Temp.                                                                          Length                                                                             No. of                                                                            High Temp.                                                                          Length                         Genotype                                                                             (mo-day)                                                                           (mo-day)                                                                           (mo-day)                                                                           Days                                                                              (F°)                                                                         (hr-min)                                                                           Days                                                                              (F°)                                                                         (hr-min)                       __________________________________________________________________________    May 1                                                                         A16    6-21 7-21 8-18 59  91    14-43                                                                              29  92    14-19                          A17    6-19 7-14 8-13 56  91    14-40                                                                              31  98    14-31                          A5     6-20 7-15 8-11 53  90    14-50                                                                              28  90    14-32                          C1640  6-20 7-25 8-29 71  90    14-32                                                                              36  90    14-01                          Century                                                                              6-21 7-17 8-31 72  90    14-29                                                                              46  89    14-07                          May 15                                                                        A16    6-29 7-21 8-21 54  90    14-34                                                                              32  92    14-15                          A17    6-24 7-17 8-16 54  91    14-43                                                                              31  90    14-25                          A5     6-24 7-17 8-16 54  91    14-43                                                                              31  90    14-25                          C1640  6-28 7-30 9-02 67  89    14-22                                                                              35  90    13-50                          Century                                                                              6-25 7-24 8-31 68  89    14-26                                                                              39  90    14-00                          May 30                                                                        A16    7-14 7-30 8-30 48  89    14-11                                                                              32  90    13-54                          A17    7-10 7-26 8-23 45  91    14-23                                                                              29  93    14-07                          A5     7-09 7-26 8-23 46  91    14-24                                                                              29  93    14-07                          C1640  7-09 8-06 9-07 61  88    17-07                                                                              33  87    13-35                          Century                                                                              7-09 7-30 9-08 62  88    14-05                                                                              41  88    13-43                          June 15                                                                       A16    7-24 8-09 9-07 46  88    13-51                                                                              30  86    13-32                          A17    7-20 8-01 9-04 47  88    13-59                                                                              35  89    13-45                          A5     7-20 8-07 9-05 48  88    13-58                                                                              30  88    13-37                          C1640  7-21 8-13 9-22 64  86    13-35                                                                              41  84    13-06                          Century                                                                              7-22 8-10 9-18 59  87    13-39                                                                              40  85    13-16                          __________________________________________________________________________

EXAMPLE 19

This Example describes the crossing of parent lines A17 with A6 toobtain soybean lines of the present invention characterized by highstearic acid and low linolenic acid contents. The hybrid F₁ seeds weredesignated AX5082-AX5083.

F_(I) plants were grown as described in Example 6. F₁ plants ofAX5082-AX5083 were grown in the Iowa State University--University ofPuerto Rico nursery at Isabela, Puerto Rico. F₂ seeds were obtained bynatural self-pollination. There were 21 F₂ plants harvested individuallyfrom each of the populations AX5082 and AX5083.

Individual F₃ seeds from F₂ plants were analyzed by gas-liquidchromatography at Iowa State University for fatty acid composition.Table XXXV sets forth the fatty acid composition of soybeans accordingto the present invention characterized by a high stearic acid and lowlinolenic acid content as well as that of the parent lines:

                  TABLE XXXV                                                      ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX5083-2-2-7                                                                             6.9     32.0    38.3   20.5  2.3                                   AX5083-3-6-1                                                                             6.8     28.2    35.0   28.3  1.8                                   AX5083-3-6-5                                                                             7.8     29.7    32.0   28.8  1.7                                   AX5083-3-6-10                                                                            8.0     23.0    24.7   42.4  2.0                                   A17        15.1     3.3    40.4   39.0  2.1                                   A6         7.3     25.2    26.4   35.6  5.4                                   ______________________________________                                    

EXAMPLE 20

This Example describes the crossing of AX4170-1-1-3 and AX4174-1-8-9 toobtain the soybean line of the present invention characterized by higholeic acid content.

The parent line AX4170-1-1-3 was prepared in a manner similar to thatfor AX4170-1-1-2 as described in Example 6. Then, F₄ seeds from F₃parent plant AX4170-1-1-3 were planted at the Agricultural Engineeringand Agronomy Research Center. Individual F₄ plants were used forcrossing. The parent line AX4174-1-8-9 is the line also used in Examples14 and 15.

Crosses were made between individual plants of AX4170-1-1-3 andAX4174-1-8-9 at the Agricultural Engineering and Agronomy ResearchCenter during the summer. The hybrid F₁ seeds obtained from the crosswere designated AX4612.

F₁ seed was planted in the Iowa State University--University of PuertoRico nursery at Isabela, Puerto Rico, in October. F₂ seeds were obtainedby natural self-pollination of the F₁ plants. Each F₁ plant washarvested individually. The F₂ seeds of each plant were maintained as aseparate subpopulation.

Thirty F₂ seeds from each of the F₁ plants, designated AX4612-1 andAX4612-2, and seeds of the parents were planted in Puerto Rico inFebruary. Fourteen F₂ plants from AX4612-1 and 11 F₂ plants fromAX4612-2 were harvested individually. A 5-seed sample from each F₂ plantand from plants of the parents were analyzed for fatty acid compositionby gas-liquid chromatography.

Table XXXVI summarizes the analysis of the fatty acid composition of theF₃ seed from the F₂ plant, obtained in Puerto Rico, having the desiredhigh oleic acid content and seed from that of the parent lines:

                  TABLE XXXVI                                                     ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX4612-1-13                                                                              12.5    4.4     56.6   24.4  2.0                                   AX4170-1-1-3                                                                             16.4    5.2     24.5   51.4  2.6                                   AX4174-1-8-9                                                                             15.1    3.3     44.4   34.4  2.9                                   ______________________________________                                    

Table XXXVII summarizes the analysis of the fatty acid composition ofthe F₄ seed obtained from the F₃ progeny from the F₂ plant AX4612-1-13having the desired high oleic acid content, as well as seed from that ofthe parents as obtained from a planting in Puerto Rico in August:

                  TABLE XXXVII                                                    ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX4612-1-13-3                                                                            10.5    3.8     64.3   20.2  1.3                                   AX4170-1-1-3                                                                             15.3    3.7     37.9   41.3  1.8                                   AX4174-1-8-9                                                                             14.6    2.9     58.4   21.7  2.4                                   ______________________________________                                    

EXAMPLE 21

This Example describes the crossing of AX4585-1-5-3 with AX5152-7 toobtain the soybean line of the present invention characterized by higholeic, low palmitic, low stearic, and low linolenic acids.

The description of line C1726, the preparation of mutant lineA1937NMU-173, and the crossing of C1726 with A1937NMU-173 to obtain lineAX5152-7 are described in our copending application, Ser. No. 461,361.The disclosure of that copending application as regards these aspects isherein incorporated by reference. The parent line AX4585-1-5-3 is theline also used in Example 14.

Crosses were made between individual plants of AX4585-1-5-3 and AX5152-7at the Agricultural Engineering and Agronomy Research center during thesummer. The hybrid F₁ seeds obtained from the crosses were designatedAX6043.

F₁ seed was planted in the Iowa State University--University of PuertoRico nursery at Isabela, Puerto Rico, in October. F₂ seeds were obtainedby natural self-pollination of the F₁ plants. Each F₁ plant washarvested individually. The F₂ seeds of each F₁ plant were maintained asa separate subpopulation.

Twelve F₂ seeds from each of the F₁ plants, designated AX6043-1 throughAX6043-5 and seeds of the parents were planted in Puerto Rico inFebruary, 1990. Six F₂ plants were harvested individually from eachsubpopulation. A 5-seed sample from each F₂ and parent plant wasanalyzed for fatty acid composition by gas-liquid chromatography.

Table XXXVIII summarizes the analysis of the fatty acid composition ofthe F₃ seed from the F₂ plant, AX6043-5-3, obtained in Puerto Rico,having the desired composition and seed from that of the parent lines:

                  TABLE XXXVIII                                                   ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX6043-5-3 5.1     2.8     66.4   23.6  2.0                                   AX4585-1-5-3                                                                             8.4     4.5     62.6   22.8  1.7                                   AX5152-7   3.8     3.8     23.5   61.4  7.6                                   ______________________________________                                    

EXAMPLE 22

This Example describes the backcrossing of A89-269077, a 2.0% linoleniccultivar, with AX7345-2, an F₁ plant of the cross AX5152-115 withA89-269077, to obtain the soybean line of the present inventioncharacterized by low linolenic and low palmitic acid contents.

Backcrossing was carried out in 1990 at the Agricultural Engineering andAgronomy Research Center. The hybrid BC₁ F₁ seeds obtained from thecross were designated AX7777.

BC₁ F₁ seeds of the cross AX7777 were planted in November in the IowaState University--University of Puerto Rico nursery at Isabela, PuertoRico. BC₁ F₂ seeds were obtained by natural self-pollination. A total of927 BC₁ F₂ seeds from the cross were planted in Puerto Rico in February.BC₁ F₃ seeds were obtained by natural self-pollination. Three seeds wereharvested from each BC₁ F₂ plant to obtain a bulk sample of BC₁ F₃ seedsfrom the population. A random sample of 480 BC₁ F₃ seeds was planted atthe Agricultural Engineering and Agronomy Research Center near Ames,Iowa, in May. Approximately 334 BC₁ F₃ plants were harvestedindividually, and a 10-seed sample from each plant was analyzed bygas-liquid chromatography to determine fatty acid composition.

Table XXXIX sets forth the fatty acid composition of the BC₁ F₃ plantcharacterized by a low palmitic acid and low linolenic acid content, aswell as that of the parent lines:

                  TABLE XXXIX                                                     ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX7777-7-30                                                                              3.9     3.5     38.3   52.2  2.1                                   A89-269077 10.0    4.4     37.5   46.2  2.0                                   AX5152-115 3.6     4.0     33.4   53.0  6.0                                   ______________________________________                                    

EXAMPLE 23

This Example describes the crossing of AX7689-1-75 with A89-269077 toobtain the soybean line of the present invention characterized by lowlinolenic and high oleic acid contents.

Crosses were made at the Iowa State University--University of PuertoRico nursery during December 1990. The hybrid F₁ seeds obtained from thecross were designated AX8095.

F₁ seeds of the cross AX8095 were planted in February in the Iowa StateUniversity--University of Puerto Rico nursery at Isabela, Puerto Rico.F₂ seeds were obtained by natural self-pollination. Each F₁ plant washarvested individually, and the F₂ seeds of each were maintained asseparate subpopulations.

Ten individual F₂ seeds from each F₁ plant were split so that theembryonic axis was left intact. The portion without the embryonic axis(approximately one-third of the seed) was analyzed for fatty acidcomposition.

Table XXXX summarizes the analysis of the fatty acid composition of anF₂ seed having the desired high oleic acid and low linolenic acidcontent and that of the parent lines:

                  TABLE XXXX                                                      ______________________________________                                                 Fatty Acid Composition                                                          Palmitic                                                                              Stearic Oleic  Linoleic                                                                            Linolenic                                        Acid    Acid    Acid   Acid  Acid                                  Seed Identification                                                                      (16:0)  (18:0)  (18:1) (18:2)                                                                              (18:3)                                ______________________________________                                        AX8095-2   8.8     3.2     72.4   14.4  1.2                                   AX7689-1-75                                                                              8.4     3.4     57.6   28.8  1.8                                   A89-269077 9.4     3.6     54.0   31.4  1.5                                   ______________________________________                                    

The present invention discloses methods for the production of soybeanscontaining low levels of linolenic acid. Such low levels of linolenicacid make the soybean products, such as soybean oil, more suitable forconsumption by reducing or eliminating the presence of undesirablelinolenic acid oxidation products which have undesirable flavorproperties. In addition, the present invention further provides theability to obtain soybean lines having various palmitic, stearic, oleic,and linoleic acid contents as may be desired for particularapplications. It is within the scope of the present invention to alter,if desired for a particular application, the soybeans of this inventionby including other fatty acids, as by genetic alteration or by any othermeans. Indeed, if useful for a particular application, the soybeans ofthe present invention may be altered as desired so long as thecharacteristic low linolenic acid trait and other desired traits areretained.

Although the foregoing invention has been described in detail withexamples for purposes of better understanding the invention, it will beunderstood by those skilled in the art that various modifications of theinvention may be practiced while remaining within the spirit and thescope of the appended claims.

What is claimed is:
 1. A soybean seed designated A16 having ATCC Accession No. 40538 and its descendents which are capable of yielding an endogenously formed vegetable oil exhibiting a linolenic acid content of less than 2.5% by weight based upon the total fatty acid content.
 2. Soybean seeds according to claim 1 that are provided as an assemblage of such seeds.
 3. Soybean plant produced by the seed of claim
 1. 